Personally, I think this is our education system wanting to try and keep up with countries like china. Which is not a good thing since we have vastly different school systems.

Back in the yellow-fear 80's, "Japan has better math scores!" was the battle cry, but ignoring the fact that Japanese schools also had a different approach to teaching math, that emphasized solving the problem rather than memorizing the formula. (Like we see in test-study scenes, where the characters ask, "How do you solve this problem?")
A little harder to teach in more individualistic countries where you can't get a high school class together to organize a culture festival or clean up the room after school, but we hadn't watched anime yet back then, and didn't know any of this.

i did singapore maths, which i really excelled at and maths was One of my good points. ever since i went to school though i am Really Bad and am now in remedial classes for GCSE idk if common core is similar to national curriculum, but if it is It sucks